The outbreak of Severe Acute Respiratory Syndrome (SARS) in 2003 alerted the world to the importance of a timely global surveillance system for public health emergencies with potential international impacts . The global pandemic was exacerbated by the initial delay in information release by the Chinese government due to the fear of political and economic consequences and ended with a total of 8,422 cases and 916 deaths worldwide . The world first learned of SARS via ProMED-mail, a non-governmental global electronic reporting system, on February 10, 2003, a day earlier than the official report by the World Health Organisation (WHO). However, the reports by both systems were published 3 months after the outbreak first occurred.
Previous studies have emphasised that timeliness is the key to the success of surveillance systems and to reflecting the time delay between response steps in the surveillance process [3–5]. Surveillance and reporting were the first two steps for further response in infectious disease control. However, the reporting process was found to be frequently subjected to political influence that affected the timeliness of the reporting and thus the effective initiation of public health interventions [6–9].
As the main surveillance network of the WHO, the Global Outbreak Alert & Response Network (GOARN) was established in 2000 . However, its efficiency is influenced by geographical and timeliness gaps due to political concerns [11, 12]. As an alternative, ProMED-mail, the non-governmental Program for Monitoring Emerging Diseases, was established in 1994 to provide early warnings about outbreaks based on information from various sources, including individuals and media reports; furthermore, unlike the WHO program, ProMED-mail does not require official clearance prior to posting reports . As one of the pioneers of internet-based reporting systems, ProMED-mail is also one of the largest publicly available reporting networks . Previous studies have confirmed its credibility [14–18]. In addition, the effects of reporting in a timely manner (without political constraints) and the efficiency of ProMED-mail in decreasing the delay in reporting have been studied through comparisons to the timeliness of reporting from the WHO [14–18]. Although internet-based sources of information not only allow the timely detection of outbreaks but also increase reporting transparency, these sources still cannot overcome the problems of non-transparency by authorities who deliberately conceal information.
The lack of transparency for political reasons, lack of consensus in policy and strategy and inadequate training and resources for health system personnel have all been cited as barriers to effective and timely global health surveillance [7, 19]. In response to the outbreak of SARS, the 58th World Health Assembly adopted a new set of International Health Regulations (IHR 2005) on May 23, 2005 to close the gaps in the global health surveillance system. As the only regulations for the global surveillance of high-priority infectious diseases, the revision of IHR 2005 responded to the needs of an effective global health surveillance system [6, 20]. IHR 2005 not only included national obligations to achieve a set of core surveillance and response capacities by eliminating technical, resource, governance, legal and political obstacles in the health system, it also required members to assess any public health emergency of international concern within 48 hours and to notify the WHO within 24 hours to ensure the timely receipt of the information. In addition, the WHO was allowed to consider reports from unofficial sources, in accordance with Article 9 . Because public health events overlap with trade and security issues, global health surveillance issues have attracted increasing attention. However, the effects of IHR 2005 on the reporting timeliness gap and the association between transparency and the reporting timeliness gap have yet to be evaluated.
The most pressing rationale for transparency in infectious disease reporting is that open communication and information can prevent delayed reports and responses to outbreaks [8, 9]. Transparency can be represented by the extent of civil liberties and the circulation of public information. Civil liberties are the rights and freedoms that protect individuals from unfair infringement by the government of the nation in which they reside and are the basic tenets of democracy. Moreover, civil liberties set limits on the government so that its members cannot abuse their power and interfere unduly with the affairs of private citizens. Countries with strong civil liberties typically also have well developed mass media that is capable of reporting infectious disease news promptly after its occurrence . Therefore, the public can receive information about a disease outbreak earlier through media or other channels in countries with better transparency. Consequently, in countries with good civil liberties, ProMED-mail might receive reports of new emerging infectious diseases from individuals or the media and release the information earlier than the WHO, which would likely receive official information from the government at a later time and post reports after receiving official clearance.
Given that the timeliness gap between WHO and ProMED-mail in a particular country might reflect the information delay due to political constraints, we conducted this study under the hypothesis that better transparency would be associated with a longer reporting timeliness gap between the official and non-official global surveillance systems. Because the avian flu and H1N1 outbreaks were the emerging global pandemics following SARS, we used the reporting of avian flu and H1N1 outbreaks as the focus of our study.